All That's Left
by eternalglitch
Summary: Which is better; showing some mercy or none at all? Once Sans thought it was the former, but now, he would tell you it was the latter. Mini-series on the ending of one of Undertale's Neutral routes. Warning for dark themes. King!Sans
1. Part One

*Warning. This fanfiction contains dark themes, including hints of alcoholism, suicide, depression, and major character death. Basically just straight up angst. Only read if you're looking for a bad time.

Takes place after the Neutral route which is closest to the No Mercy run.

Betaed by the lovely FlightlessTree.

* * *

Sans waited for the phone to pick up, but instead it sent him straight to voicemail.

Figures.

He stared down at the phone in his hand, eyes pitch black, half tempted to hang up, but he didn't. He needed at least some sort of closure.

"heya," Sans said candidly, tapping his fingers on his desk. "is anyone there?" _of course not._ "well, i'll just leave a message…"

Sans sighed, giving a half-hearted chuckle. "it's been a while, huh?" He trailed off, closing his eyes, remembering the human.

Their dirty pink and blue sweater, the tousled hair, the scared and hunted look that haunted their every step. He wondered what they were doing right now.

"...things have gotten pretty bad here," The skeleton continued softly. "everyone considered a leader disappeared overnight." He stood, walking over to the window to stare outside. It was silent except for a bird somewhere, chirping softly. That was right- it had been a day just like today the kid had left the Underground, hadn't it? "it's gotten so quiet."

Sans reached up, grasping the red scarf hung loosely around his neck. "there's a bad feeling hanging over everyone. like everyone's going to die here, trapped in the dark…"

A wry grin made its way onto Sans' face, and he leaned his forehead against the glass as his reflection gazed back at him. The different clothing didn't suit him, he thought, studying his changed appearance. The kid probably would've found this hilarious… all the more reason not to tell the truth. He didn't want them having any joy at his expense ever again.

"i bet you're wondering why i'm not ruler," he continued. "eh." _you don't need to know._ "i'm not cut out for something like that. i like to take it easy, y'know?"

The lie slipped out, easy to say because it _felt_ true. Even now, he himself could barely believe what had happened since the kid had left. Sans' face slowly darkened, and his grin grew. "...that's a joke." He studied his reflection one more time. Then he sighed, slipping back into his chair. "this is what happens when people like me take it easy."

Papyrus, gone.

Undyne, gone.

Alphys, gone.

Asgore, gone.

Someone Sans once joked with, gone.

All Sans' fault. All Sans' responsibility now.

"hey, at least things are less crowded now. 'cause, y'know, of all the people you killed." Sans examined the phone. Welp, almost out of time. "hope that was a good experience for you."

It the human's decision to gain LOVE; it was the human's decision to hurt others instead of risking the chance of getting hurt themself.

"...just kidding." Sans' eyes dimmed, and he growled the last bit out. "i don't really hope that."

The human had chosen to do it all, and yet Sans had chosen not to stop it. At the end, at least, he should had taken revenge. But that mistake was done and over with; now Sans had to keep moving forward.

"go to hell." Sans hung up with a click and rubbed his face with one skeletal hand before he got up. He adjusted his crown. He had work to do.

At this point, there was no turning back. Sans would keep walking the path that had been given to him. He could still remember with unusual clarity how all of this started, so soon after the human had left the Underground...

.

 _-One year prior-_

"i like to take it easy, you know? you're looking at the wrong guy for this," Sans pleaded, backing away. The monsters stared back at him, pressing close to him, encircling him, _trapping_ _him_. Sans felt like he was drowning in the expectations he saw reflected back in their eyes. "find somebody else, okay? i- i can't be king, okay? that's… that's a really bad idea. i can't…"

"Please, Sans!" One of the dog sentries begged. Dogamy, Sans recalled dimly. "There's no one left. We know you had something to do with Asgore while he was alive. You can't just abandon us! Even… even Dogaressa… she's dead, Sans… Undyne, too. No one is left," Dogamy repeated, voice breaking. "No one left but _you._ "

There was no accusation in Dogamy's voice, but Sans sure felt like there was. Why was Sans still alive when so few others were? Sans backed up some more, shaking his head, and bumping into a wall. His eyes widened; he was being surrounded by more and more monsters. The voices rose and Sans' own words were drowned out by the wishes of others. His hand reached up and curled around the red scarf that hung from his neck. A medallion of his failures, a memento of what once was.

Indeed, Sans was the only one left. There really _wasn't_ anyone else left.

 _pap…what would you do if you were here right now…? what would you want me to do?_ Somehow, Sans knew the answer, but that didn't make it any easier. This whole mess had happened because Sans had taken it easy. He had looked down at the kid, hissed at them to go to hell, but still refused to lift a single finger to stop them. He let them merely walk out of his life without even obtaining the last soul needed as their payment for their cruel deeds… Sans supposed the time for such complacent acts was over.

Sans took a deep breath and lifted his head. His mouth moved, and all of a sudden the monsters went silent, so silent that all that could be heard was Sans' rasping voice.

The voice of the new king.

Moments before his words had quivered, but now they sounded firm. Confident. Something Sans didn't feel at all.

"all right. if you want me that bad… i'll do it."

As cheers rang around him, Sans' grip tightened on the red scarf. He glanced back at his and Papyrus' old house one final time before he moved, starting to walk down the long path to the New Home. Monsters followed him, calling out the news to those crying and broken along the way. The crowd grew, and the short skeleton had to suppress the hysteria creeping through his very soul.

Sans closed his eyes for a second, letting out the breath that he had held for so long.

In the end, his own judgment had caused all of this. He knew what the human was, what the human could do, had _done_ , and yet…

Welp. What was done was done. Sans made his bed; now he had to lie in it. He could only look forward, pushing off the clawing emptiness that screamed at him in the form of a ragged red scarf.

.

And even with a new king, things were bleak.

What had the Underground been expecting? Maybe someone else could have pulled the Underground out of the depression and hopelessness that had plunged over the kingdom in a single day, someone braver and more cheerful than Sans, but in the end Sans was only a reflection of the people he now governed.

Tired.

Broken.

Hopeless.

The paperwork- much more of it than what Asgore used to deal with- lay in perpetual mounds around Sans' new desk. Trash littered his new abode, and Sans was only reminded that no one was there to pick up after him anymore. His fridge was constantly empty, and Sans didn't have it in him to cook anymore.

He had tried to make a quiche once, but his reason for that attempt was silent. She was probably gone, just like the rest.

Sans wondered what her name was. She must have loved the human; Sans could remember his promise to her quite clearly in stark contrast to the rest of his muddled memories. Sans bleakly wondered what she had thought when she turned to dust at the hands of the same one she had tried to protect?

Sans wished he never agreed to that promise.

He examined the vacant fridge for a moment longer, remembering when he had opened it once upon a time to find spaghetti attempts overflowing onto his side.

He slammed the door shut, and rubbed his face.

For once in his life, Sans wished the tears would just come and get this over with, but he was simply too tired. The tears would no longer come.

.

Sans rubbed his head with a sigh. "so? what was so important in here you just _had_ to show me?" He asked as the elevator descended.

The monster uneasily shifted, fumbling with their keys. "That's, erm," they trailed off, and then frowned. "We found some signs of- of life in the basement down here while sorting everything. We thought you should, ah..."

"is it alphys?" Sans asked quickly, suddenly alert. She'd been missing ever since what the citizens of the Underground were now calling the Second Fall.

"We don't know."

Sans studied the monster- they looked nervous. The elevator doors slid open. "wait here," he murmured, not missing the relieved look the monster shot him as he hurried down the corridors.

There were no signs of life in the first room. Sans squinted as he looked around the dusty laboratory. Messages stuttered to life as Sans walked by but he ignored them, focused on his mission alone.

Hesitantly, Sans headed for the largest room- he could dimly recall the layout from the time he worked here long ago- and paused. His white pupils examined the dark entranceway for a long moment before he took a deep breath and entered the room.

This room was filled with beds from wall to wall. However, what really caught Sans' attention was the two monsters crowding around one bed in particular.

Sans didn't know who or what these monsters were- they all looked misshapen, strange, and starved. One appeared to be a giant white dog, the other some strange type of bird. Judging from their gaunt appearances, Sans suspected the many piles of dust in the room didn't just come from a lack of regular cleaning.

Sans approached them, slippers silently sliding over the ground.

He didn't understand what these monsters were. He didn't understand what Alphys had been thinking in the last moments of her life.

But Sans understood quite perfectly what the pile of dust on the bed, a pink phone lying next to it with its battery still barely alive, represented.

Sans sank to his knees, a soft sigh rattling past his teeth. Again. It happened again.

He was too late.


	2. Part Two

This is probably going to be roughly five parts.

Thanks for reading!

Betaed by FlightlessTree.

* * *

Someone banged on the door, waking Sans up. "King Sans!"

The skeleton groaned, sitting up and peeling a piece of paper off of his face. He would never get used to that superfluous title. He glanced at the paper for a moment, puzzled, only to realize it was just a request for another city expansion.

The crowding had lightened a little- over two hundred monsters had vanished overnight, y'know? But it was still a major problem.

"what is it?" Sans asked, yawning.

The door crashed open. It was the shopkeeper from Snowdin, eyes filled with tears. "Please! King Sans!" She whimpered. "You have to do something. Please, oh my god, my child- she… she…"

"whoah, whoah, slow down. what's wrong?" Sans asked, rushing to her side. His crown slipped, no fur, horns, or ears to hold it steady, but Sans shoved it back onto his head with a quick flick of his wrist.

"My child won't wake up," the shopkeeper whispered, and Sans stiffened.

Shit. That was the fourth this month.

"let me see what i can do, okay? maybe we can get her to wake back up," Sans coaxed urgently, grabbing the shopkeeper's hand and pulling her through the shortcut with him. He no longer kept his powers secret; why bother? It was ironic, really; now he only tried to hide his weaknesses. That was what kings did, Sans supposed.

They landed outside of Snowdin's Inn and rushed inside, Sans trailing just behind the rabbit. Sans followed her up the stairs, hesitant to see what he knew was coming. The urge to drag his feet was tempting, but Sans forced himself to hurry.

Whether Sans liked it or not, he had responsibilities now- not just for him and his brother, but the entire Underground.

The small rabbit was lying on the large guest bed, her figure dwarfed by the mattress. Sans would have thought she was dead if not for her chest, barely moving up and down. The shopkeeper sank to her knees besides the little girl, whispering reassurances and pleading for her to wake. Sans knew the shopkeeper had more little ones somewhere; he wondered where they were.

Finally, unable to tear his eyes away from the frantic mother, Sans approached the bed. "hey kid," he murmured, the shopkeeper looking up at him hopefully with teary eyes. "it's uh, the king here. and i know that things seem pretty hopeless now, but- but ya gotta stick with us, all right? it's going to get better, i promise. everything is going to get better."

The words tasted strange in Sans' mouth, thick and sticky, how he imagined lies would taste. If Sans didn't believe what he was saying- how could anyone else? But he kept talking, and soon the mother joined, their voices weaving together a web of false hopes and promises until their throats were both raw and the next day was upon them.

He stayed in that room for hours, until the small child's body had long since crumbled into dust. Her mother cried and screamed until she could no longer speak.

Sans could only watch, hating himself, hating how damn useless he was, how he had once again failed, how he had the nerve to whisper lies he didn't even believe.

Sans forced himself to go to the funeral- one of many Sans had attended since becoming king just a few months ago- and when he finally managed to return back to his desk and paperwork he swept it all off the desk in one angry motion.

"useless! it's all useless," Sans hissed bitterly. He dropped his head into his hands and stayed in that position until he fell asleep.

.

Sans nodded at Grillby, quickly pocketing the bottle of ketchup after he had finished the stronger stuff. The bartender watched him, glasses glinting, as Sans turned to go.

"Sans…" the fire monster finally said, his voice a raspy crackling not unlike the sound of his element. "Are you doing… all right?"

Sans paused on his way out, glancing back with a mirthless grin. "'course i am, grillbz, who do ya take me for?"

The door swung shut with a clatter, and Sans didn't look back again. He knew that the bartender was probably still watching him, worried over the skeleton that had once come by nightly to get drunk and ramble to the incommunicado monster.

Sans started walking, too tired for a shortcut and social interaction. Who knows, maybe a bit of fresh air by himself was just what he needed.

It was on his walk back home that he bumped into the flower.

.

Sans plopped down next to the anomaly. Neither spoke. The flower looked harmless, yellow petals drooping and a wilted appearance giving the impression that he hadn't slept in a long time. If flowers even needed sleep, that is.

"so, buddy, what are you doing, skulking around here?" Sans asked. "haven't noticed you in a long while. almost thought ya had finally decided to move on."

"I don't feel like explaining myself to you."

"no, you wouldn't, huh?" Sans acknowledged. "what're you waiting for, then? you seemed pretty happy when the human came. why didn't you leave with them?"

"They… they weren't who I thought they were." Flowey said flatly. "If they had been, they would've recognized me. They wouldn't have just ran off like that…"

"tough luck, buddy." Sans said flatly.

The flower finally turned and glowered at Sans. "Like you have it any better," he snapped. "How is that going, by the way, being the new king?"

"eh. i'm not really cut out for something like this, but y'know. no one else can do it but me, so might as well just do my job."

Flowey giggled softly, taunting Sans as he leered up at him. "I wonder, Sans, if you really are aware of as much as you say you are. That wasn't the first time the human went through the Underground, as I'm sure you know."

Sans shrugged, not responding.

"One timeline, even, ended up very similar to this one. It didn't last very long, of course; the human came back, experimented some more, they always did; but for a while, it was Papyrus as the ruler of the Underground."

Sans twitched, his hand involuntarily reached for the red scarf at his neck.

Flowey smiled; the meaning behind the motion did not escape him. "You were there, too, of course; and for a while, everything seemed fine. Until a human came. Everyone expected the king- Papyrus- to do the right thing and just kill the human for its soul. But Papyrus was afraid. And you couldn't let your precious brother go through that alone…" Flowey's smile widened. "I wonder. This time. Are you going to do the same thing?"

Sans shifted, the meaning behind Flowey's words clear. It wasn't a question of _if_ another human would come- but _when._

Sans wondered which human it would be.

"so tell me, buddy; the human from this timeline. are they gonna come back this time as well?"

"...No. I don't think so. They no longer have the power to do so." Flowey muttered, shifting and refusing to meet Sans' gaze. "Last time they held the power to reset for a while but… this time was different. Like they grew bored or- or something. But that's okay! Because they couldn't have been _my_ human...and- and since they weren't _them_ , then I just have to wait! I might have been wrong this one time but I'm sure that one day Chara will… will…" The flower trailed off, and turned away. "I'm sure they'll come back for me," the flower finally whispered, voice cracking. "They _have_ to."

Sans didn't reply. He stood up and stretched, then turned to leave.

Unlike the flower, Sans saw no point in waiting with some kind of false hope.

Sans had no one to wait for anyways.

.

"My king!" One of the new guards rushed in, battle armor clanking noisily. The tension in the monster's voice caused Sans to sit up, abandoning the hot dog he had been eating.

"what is it?"

"A human has been sighted!"

Sans dropped the hotdog, ignoring the ketchup now staining at least three very important documents.

"where?" He asked, his voice hoarse.

The guard quickly told him, and the two rushed from New Home. Sans hated how far away the Castle was from Snowdin; it seemed everything always happened in those snow-covered woods nowadays.

"My king!" One of the villagers spotted Sans, and quickly went out to reach him.

Sans, huffing slightly, narrowed his eyes as he looked around. "where is it?"

"It got past us, my king."

Sans blinked, and then he sighed. "it got past- how did a human manage to get past everyone?"

"The puzzles no longer work, especially since you ordered us not to improve them- if you'd just-"

" **no**. don't touch the puzzles." Sans ordered, already pulling out his phone and quickly hijacking the Labs' cameras. Even with Alphys gone, Sans had assigned two monsters the job of up keeping the security measures and lab.

He quickly skimmed through and found the human, a small creature that was racing through Waterfall and scrambling for cover whenever a monster approached.

Sans shifted, expression disturbed. The child was not _them._ Sans didn't know if he should be relieved.

This child was taller, with brown eyes and black curls. Her skin was darker and the clothes she wore weren't old or worn or striped.

The villager hovered by Sans, one of the remaining dog sentries, refusing to leave. "My King…?"  
"what?" Snapped Sans, before realizing the tone of his voice and taking a moment to shove his outward demeanor back into his normal, relaxed and amused persona. "...sorry. i mean, what is it?"

"Are you going to take the human's soul?" The sentry asked. Sans could hear the waver in her voice, an attempt to sound professional but the emotion was still there. Hope. Something Sans hadn't heard in a long time.

" _Everyone expected the king- Papyrus- to do the right thing and just kill the human for its soul… I wonder. This time. Are you going to do the same thing?"_

Sans closed his eyes. According to Flowey, even with Papyrus ruling, the humans that fell down to the Underground… didn't get a happy ending. And if his cool brother couldn't find a solution solution, how could Sans do better?

Sans turned away, pulling up his hood. His clothes were different now- the hoodie was purple, the sign of the old royal family on the front to indicate who he was.

Sans missed his blue hoodie.

"...yes." He said softly, his voice hard. Then, louder, so all the villagers watching him could hear. "when we find the human, i will take its soul. and eventually, we will be free."

The cheering didn't make Sans feel any better. He turned, and used a shortcut to go greet the human, the applause ringing in his head.

.

"heya kiddo. why don't you turn around and greet a new pal?"

The human froze, jerking around to gaze at Sans in wide, petrified terror. A scratch was apparent on her face and her arms were covered in bruises. The monsters had not been kind to the human this round.

"Please," the human asked, voice quivering. "I'm- I'm just trying to get home. I'm just a kid- a little girl! I'm not going to hurt anyone, _please_ just let me go home…" She backed away from Sans, watching him with nervous, scared eyes.

Sans smiled at her, and for a moment she looked hopeful- her shoulders slumped with relief, and she hesitantly stepped forward. Too bad that her hope wasn't what Sans was worried about.

"sorry kiddo," he said, tilting his head at her, finality in his tone. She froze, eyes widening. "i'm afraid i can't let you pass. even if i did, kiddo, hate to break it to ya but to leave this place, you need a boss monster's soul… and i'm afraid that we're fresh out of those. i'm the closest thing there is, and unfortunately i'm not that powerful."

Sans made sure it was quick and painless; this human's mistake had only been to be at the wrong place at the wrong time.

The first child's soul was yellow.

Sans wondered if the cheers of the monsters that greeted him when he returned were loud enough to drown out the cries of the little girl.


	3. Part Three

My apologies for the wait; we've been pretty busy lately. c:

Betaed by FlightlessTree.

* * *

Sans gently cleaned the jar, wiping the surface with a cloth before setting it back onto the windowsill. He studied the dust inside for a moment before he sighed.

"nice day, isn't it, papyrus?"

Sans turned his head away, his eyes narrowing into slits. "..."

"i wonder if in the other timeline… you hated me for killing humans for you." Sans stuffed his hands into his pockets, walking over to the door. Without looking back, he whispered softly, underneath his breath.

"i guess it really doesn't matter now though. now there's just me, and i'm pretty sure i hate myself enough for the both of us."

.

The second human's soul was teal.

It was an unusually cold day in the Underground- probably winter up on the surface, but Sans had no way of verifying if the tales of seasons were true so he wasn't sure- when the child stumbled into the Hotlands.

Sans was impressed this one made it so far; most monsters attacked humans with a vengeance after the Second Fall.

This human's temperament didn't help, either. To get that far… Sans had several more funerals to attend, thanks to the sword Sans had tossed into the lava after the fight.

Sans attempted to reorganize the Royal Guard again- the leader, Dogamy, was trying, but even with Dogaressa he hadn't been strong enough to stop _the_ human- but to no avail. Without Undyne as a leader, the entire group was good for little more than keeping watch as sentries, alerting Sans when problems arose, and helping out monsters in the Underground.

Sans was the one to whom killing the humans fell every time.

He wondered why they were always children. It would be easier if they were adults.

Sparing one last glance at the piles of dust around the battle zone, Sans sighed. Welp. At least the guilt was smaller this time… even if Sans knew deep down the kid had only struck out in self defense.

.

Even harder were the third and fourth human souls.

Both souls were green, one a darker shade than the other.

The humans- still children, Sans had noted in dismay- were both boys, and the shorter one clung to the other's arm as they raced through the Underground.

Sans had originally bumped into them in Waterfall.

The younger one was shivering and the older one's eyes darted around as he shielded his brother and warily backed away.

"...looking for a weapon?" Sans asked. "sorry buddy. i don't think you'll find one around here."

"You _monsters_." The boy hissed, trying to look dangerous even though Sans could see the fear in his eyes. "Why are you attacking us? What did we do to you?"

"heh. nothing. it's what you _could_ do that matters here." Sans said conversationally. He had to look unconcerned. Amused. Monsters were _watching_ … "you could, for instance, kill a lot of monsters here for no good reason-"  
"We would _never_ -"

"or, even better, you could help monsters go free by just giving up." Sans smiled, locking eyes with the boy in front. "i hate to say it, but you're just as trapped as the rest of us anyways, so there's no point in running anymore."

The smaller boy began to cry as Sans' hand darted out, starting the battle as both humans' souls turned blue with a dinging sound.

"...sorry 'bout this. it's nothing personal," Sans said, yanking the humans to the ground so they hit the floor with a loud thump. "just business." He summoned gaster blasters with another gesture, determined to put the humans out of their misery as quickly as possible.

He didn't count on the older boy on leaping at the younger, shoving him out of the way so the child went tumbling across the room and looked up in horror, crying, screaming, reaching for the other child.

The older boy smiled sadly and mouthed a word.

The gaster blasters roared, drowning him out, and Sans pocketed the forest green soul just before it crumbled away to nothing.

He turned, his left eye glowing bright blue and casting its glow around his surroundings. The other child scrambled to his feet, legs shaking.

"Brother," the boy whimpered, and Sans froze. "No… nonono…" The child trembled, staring at Sans in horror, before spinning around and fleeing, running as fast away from Sans as possible.

Sans didn't move, hands clenching as he tried not to think about the awful irony of the entire situation.

.

Sans caught the boy in Hotlands. He would have caught them sooner- they were slow, weak, and it was clear the only reason they had survived this long was because of the older boy- except Sans had needed a few moments to calm down after the experience of taking the other child's soul.

He stared down at the smaller child who was crouched at his feet, still shaking in terror and crying. He had given up.

Sans' pupils flickered out, his black eye sockets staring down at the child. He supposed he could offer condolences to the child, but that probably wouldn't help. It was hard to see the good the humans' souls would give the Underground when all Sans could think was he was a filthy brother killer now too.

Wouldn't the _other_ kid have been ecstatic about that?

Bones shot up from the floor, and Sans quietly pocketed the light green soul as blood splattered across the ground.

 _Murderer._

.

"annnnd... i just… don't wanna do this anymorrrre, y'know?" Sans slurred, resting his head on his arms at the bar.

Grillby was silent, cleaning a glass, the same as always. He was a good listener. Sans liked that about him.

"i mean… they're all goddamn children, who'm i to say if it's ok to kill 'em… pap will be soooo disappointed in me." Sans gloomily lifted his head to peer into his cup before holding it out towards Grillby hopefully.

The flame turned, and Sans could tell he was giving him a deadpan look from experience before taking the cup away and instead handing Sans a regular mug filled with cold water.

"awww, don't be like that, grillbz, have some pity for your old paaal…"

Sans scowled at the fire monster's pointed silence, tapping his fingers on the bar counter as he surveyed the empty shop with bleary eyes. "wellllll. if you're gonna be like that then 'm just gonna… head home…" Sans muttered, standing up and swaying.

The bartender paused, setting down the glass. Sans shot him a glare, waving him off. "i know where m'house is, grillbz, don't need help."

Sans staggered outside, cursing as he realized it was probably four in the morning. Papyrus would be mad at him for staying out this late.

Sans managed to make his way back to his house, relieved it was just a short and familiar walk. The issue came, however, when Sans realized he had left his keys somewhere. Probably at the bar.

Sans squinted at the door, scowling, before snapping his fingers. He took a shortcut inside, expecting to see a sleeping Papyrus, waiting for him with a scowl on his face as always.

Instead, Sans stared dumbly at the new furniture, a few beds housing monsters that _definitely_ were _not_ Papyrus.

His hand darted to his neck, to that red scarf draped around his neck.

Reality settled back in.

Sans was glad that, even drunk, he reflexively shortcutted, landing with a thump in New Home.

And finally, finally, _finally,_ the dam broke and Sans sank to his knees, his vision going blurry with tears.

His shoulders started shaking, and Sans could barely think straight as his breaths started coming in desperate gasps of air.

"papyrus," Sans whimpered, hiding his face in the red scarf. "please come back to me, bro. please, god, i'm beggin' you. please don't end it here, like this. please reset. please. please. _please._ " Sans didn't know who he was asking, but he kept babbling, shoulders heaving as he felt the walls closing around him.

It was too much. He felt like there were eyes, watching him every second, every moment, invisible chains wrapping around his limbs and choking him until he couldn't breathe.

He didn't know how long he lay there, screaming until his voice was gone, rasping out his dead brother's name over and over until Sans' last tear stained the red cloth a darker hue and once again, Sans had no more tears to cry.

He didn't drink again after that.

It was better to hate himself and lose sleep over his bad deeds than go through the realization his brother was dead all over again.

.

"King Sans," the old turtle monster greeted him, leaning against his store's window. "What can I do for you?"

Sans shrugged, leaning against the counter. "just wanted someone to bounce a few thoughts off of you," he said. "ya mind?"

Gerson gave a toothy grin. "Of course not, wah ha ha! I always have time for royalty."

Sans looked away. "i'm not really royalty," he murmured uncomfortably. "mostly just a stand-in."

"Oh, silence, you're doing a job no one else could right now." Gerson said sternly, squinting at Sans. "And between you and me, you're doing one hell of a fine job at it. Don't listen to whatever anyone else says."

"heh. i can only hope so," Sans replied, looking back at the old monster and grinning at him. After a moment though, Sans sighed. "anyways. i came here to ask about the war between monsters and humans."

Gerson quirked an eyebrow at Sans, leaning forwards to study the skeleton. "Oh? What do you want to know?"

"well. right now, a lot of monsters think everything will get better to go to the surface. but i'm uh, not so sure that's a good idea, specially after the second fall and all."

"You think they'd attack us." Gerson stated, settling back and crossing his arms.

"...yes."

"It's not an impossibility," Gerson said, nodding. "And you've only really experienced a few humans, so you don't know what the adults are capable of, hmm?"

Sans nodded, and Gerson tapped his clawed fingers against the desk. "Well, I'll tell you what I can, but this was all a long time ago. Humans might have changed since the war." Gerson glanced at the Delta Rune, thinking. "Originally, there were a lot more of us monsters. Nearly half as many as the humans; still not enough but many more than the few thousand that live today. We also were stronger; our magic was much more powerful because we had more hope. And… even with all of those advantages, we were hopelessly outmatched."

Greson looked at Sans, his yellow eye narrowing. "I lost my right eye in the final battle," he admitted. "And since we've been weakening down here, I can only imagine the humans are growing stronger with all of the room available on the Surface for them. War right now… I wouldn't suggest it."

Sans sat up. "...i see." He nodded at Gerson, stuffing his hands in his pockets. "thanks for the information," he said quietly, turning to leave.

"Sans!" The elderly monster called. Sans paused, the lack of the title startling him.

"...Come by if you need to talk again," Gerson asked, and Sans grinned at him for a second before taking a shortcut to the Barrier.

He needed to straighten out his thoughts.

.

Sans understood Asgore all too well by now. Even if Sans _had_ been a boss monster- which he wasn't- he would have been hesitant to take one of the human souls and venture past the barrier for help. The monsters had killed nine human children by now for the sake of escaping- and who knew what the survivor had said about the Underground when they escaped.

Sans had to face the facts that maybe what was waiting for monsters past the barrier… was far, far worse than the current situation.

Sans wondered if it was possible to convince the other monsters to stay in the Underground forever.

Probably not.

However, another idea had come in Sans' thoughts; in Sans' journals, one of his few personal belongings he had brought from Snowdin with him on top of all of Papyrus' things and the small jar of dust, where he had written about one of the times someone had gone through the Underground initially. Apparently, an event that hadn't happened once but multiple times, even within this very timeline, although Sans could not remember it.

Flowey had gotten his roots on the six human souls at one point and actually _absorbed_ them. And, even though he was missing one soul… that had still given him some control over the timelines.

Enough power to reset? Sans wondered. As ruler, Sans had realized with a sinking feeling that it would be up to him to absorb all seven human souls to break the barrier.

Sans spared a glance at the four souls, all softly bobbing up and down in their containers, before he turned away from the barrier with a sigh.

He was really tired.


	4. Part Four

The next part is the end.

Betaed by FlightlessTree.

* * *

Sans woke up with a start when he felt his phone vibrating in his pocket.

He quickly sat up, hand darting for the device. He flipped it open and studied the screen, expecting a human alert.

 _ **ID CALLER: LUCKY#7**_

Sans froze, his grin shrinking a bit. This was a human alert all right, but not the kind Sans had been prepared for. It was _the_ human… calling him? Why? Sans had left the voicemail a few weeks ago but he hadn't ever expected a response.

Sans hesitated, finger hovering over the answer button. Did he really want to talk to them? Maybe he could wait and they'd leave a voicemail.

Or maybe this was the only chance Sans had.

He hit answer, a bead of sweat already dewing his skull.

"...heya. sans here. ya rang?" He asked carefully.

"Sans." The familiar voice said, sounding tired. "...I got your voicemail."

"oh. glad to hear it, buddy. so? what does a dirty killer like you want now?" Sans asked, closing his eyes as he forced his stiff shoulders to relax. "i mean, you killed nearly every single monster you could get your hands on. it's amazing one or two escaped after you nearly got rid of 'em for good."

"I… that's not…" The human sighed. "Look. I know what I did was wrong, okay? I didn't think it would be… um…"

"permanent?" Sans asked flatly. "neither did i, **frisk**."

Sans heard a sharp intake of breath on the other line. Sans picked up a pen on his desk and rolled it between his fingers. "yup. i kept track of a few of the excursions you had in the underground. kinda surprised that _this_ is the one you decided to keep. did you get bored so soon?"

"I… I'm sorry," Frisk whispered, voice shaking. "Look, it's hard to explain but- I had to leave the Underground _immediately_. I was losing control- my next run probably would have been worse! I could have gone and killed everyone!"

"you nearly _did_ this time."

"I'm sorry…I wish I could go back but I just _can't_...Not again."

Sans' pupils flickered. He smiled, propping his feet up on the desk. "...you made a big mistake, buddy. leaving me alive like this. you're just lucky i'm more laid back than undyne had been- unlike her, i don't feel the need to hunt you down on purpose. but. if i ever see you again…" Sans smiled grimly, black eyes narrowed in cold anger. "well. i'm sure you can imagine what a bad time you'd have."

.

Five months later, Sans took the fifth human soul. It was blue.

Sans didn't want to remember the child's impassive eyes that stared up at him without fear.

"Just get it over with," he remembered dimly. The child hadn't even tried to run; they must have come to Mt. Ebott for a specific outcome; they didn't seem to care much how it was achieved.

Sans hoped that whatever human souls experienced after being taken was not unpleasant.

After this, he tried to tune out each human's individual traits. They would just haunt his dreams that much longer.

So far, none of the humans had reset; he kept careful track in his journals of each day in case, and yet he hadn't found any child capable of resetting. Maybe only red souls could reset. The flower hadn't done anything suspicious, either, as Sans hadn't seen him anywhere since their last conversation.

Sans was beginning to lose his strength. He slept more when he could… but nightmares kept him up and left his eyes perpetually marked with dark circles. He hid from monsters when outside the castle, using shortcuts excessively just to avoid simple conversations. Sans knew that if he was another monster, his HOPE would've gone down significantly; as it was, his measly 1 HP remained as it was.

Maybe Sans would just fade away peacefully, he thought sometimes. He would go to sleep and turn to dust along with his worries.

At times, it was tempting- ridiculously so, and Sans hated it. The thought wasn't a foreign one; it had come and gone in the past, too, but Papyrus had always been _there._ A reason for Sans to get up in the morning and paste a grin on his face.

Sans could even make himself turn to dust- just as he had done to the humans, one shot from the gaster blasters and it would all be-

No.

Sans no longer had that option.

He was king, and he must keep going. If not for his own sake, then for that of everyone he'd already let down.

He was trapped in a spider's' web of responsibility, and there was no way out now.

.

The sixth soul was pink. It was nearing the second anniversary since the Second Fall; all of the monsters were especially tense. This time, Sans hadn't even seen the human- Dogamy had delivered the soul to Sans himself with a look of somber pride.

Sans didn't want to admit he was glad someone else could bear that burden as well.

Sans sipped his ketchup and studied the seven containers.

Yellow.

Teal.

Dark green.

Light green.

Blue.

Pink.

 _ **Empty.**_

Sans spent many hours gazing at the empty jar, wondering what he'd do upon acquiring the last soul. The idea that Sans could take the souls himself and reset _everything…_ it was tempting.

Sans wondered when he had started to hold onto false hopes again, but it didn't matter. Not really. Sometime soon, Sans would find out what would happen whether he liked it or not.

.

One day, Sans decided to take a look around the Ruins. They were quieter than the rest of the Underground, and Sans was curious about the fate of the stranger with which he used to have such lengthy conversations.

Besides, if a human happened to fall, Sans could quickly take care of them.

Sans took a shortcut to avoid sight of the old puzzles, landing where he had first met the seventh human. That day seemed so distant now. The large purple door was cracked open, the human with the pink soul having neglected to close it behind them.

Sans gently nudged it further open and entered, noting the now-dirty walls and layers of dust. It was a long hallway, and Sans was surprised to see a dark room at the end apparently connecting this hallway to the rest of the Ruins.

Curiously, though, Sans found himself with company.

"so here you are." Sans stopped to look at the flower vexedly eyeing him from the center of the room. "it's been a while, huh?"

"What are you doing here? This is my area now!" Flowey snapped. "I don't need someone to talk to, if that's what you're thinking."

"not at all," Sans said amicably. "just looking for some peace and quiet… and uh, curious to finally find out what happened to an old friend of mine."

"You mean Toriel." Flowey said, an uncertain look flickering over his face. He was silent, studying the ground for a moment, refusing to meet Sans' gaze. "...I knew her," he said flatly. "I mean, you probably knew that, but… She stopped me from killing a certain human the day she died."

Sans blinked. This wasn't the sort of behavior he expected from the flower. His entries made it clear he'd killed the flower dozens of times… perhaps the past two years had changed both of them.

Sans started walking to the next room, brushing past Flowey. He hesitated for a moment and turned back towards the dark room. "heh. thanks for the info, anyway," he said. "...hey. i was wondering…"

Flowey glanced up at him for a moment, and Sans shrugged. "...no. nevermind. no need to give me such a thorny look, i'm leaving ya alone now."

After Sans shut the door, leaving the flower in the dark, he looked down at the untouched pile of dust in front of him.

He grinned, sitting down beside it.

"so. toriel, huh?" Her name left a strange taste in his mouth. Like the kid, Sans avoided voicing the name even in his thoughts until formally introduced, so he hadn't thought of her in such a close way in years. "name's sans. 'course, i told you that pretty early on, unlike yourself. it's nice to formally meet ya."

Sans' shoulders slumped. He pressed his hands over his eyes.

"knock knock…" He said softly. He studied the pile of dust silently and thought of moments long gone.

Hours passed.

"...that's what I thought," Sans whispered. "nobody's home."

He got up and left, the flower already long gone.

.

The phone vibrated, inching along the desk's surface as Sans stared at it blankly.

 **ID CALLER: LUCKY#7**.

 _...click._

Sans turned the phone off and stood, leaving the phone on the desk and taking a shortcut.

He had better things to do than obsess over some brat apologizing again and again but fixing nothing.

.

" _SANS!"_

 _Papyrus turned and faced him, holding out a hand. "COME ON, BROTHER, WE'RE GOING TO BE LATE FOR SENTRY DUTY!"_

 _Sans grinned, reaching for the hand. "sorry bro, sleeping was just such a romantic idea today that i couldn't help but give it a few more winks."  
_ " _SANS! I'LL LEAVE WITHOUT YOU!"_

 _Sans laughed, stuffing his hands in his pockets. "hold on, hold on, i'm coming," he said, quickening his pace._

" _Are you?" A voice giggled, and Sans felt his legs and arms get caught._

" _wha-?" Sans struggled, but he couldn't move. "papyrus?" He called, looking around._

" _He's gone~" The voice giggled. "Strange…. And you're still here…?"_

" _papyrus?" Sans yelled._

 _In the distance, he thought he heard his brother's voice._

" _SANS!"_

" _papyrus! wait up, i'm coming!" Sans struggled, but he couldn't budge from his restraints._

" _SANS!"_

" _wait! don't leave without me," Sans asked, his voice cracking for the first time since he could remember._

" _SANS!"_

Papyrus' voice grew distant, distorted, and Sans frowned, struggling.

"KING SANS!" The voice repeated, but this time it wasn't Papyrus.

Sans' eyes shot open and he floundered, suddenly finding himself entangled in his sheets. "wha-?" He asked, disoriented. Sans looked around blinking sleep out of his eyes. Strange. He hadn't actually slept in a bed in… weeks. Normally it was just his chair because he'd fallen asleep doing paperwork. He spotted one of his sentries looking nervously into the room, and Sans blinked again, suddenly alert. They didn't come into his private rooms unless something important was happening. "what is it?"

"The seventh human is here," the sentry stuttered, clutching their sword closely.

Sans shot out of bed, glad he slept in his clothes. "where?" He demanded, plopping his crown on top of his head and charging towards the door.

"They- they're already in the Core," the sentry said. "We think they're coming here…" The sentry trailed off, and this time Sans saw the fear flashing across his face.

Why was the sentry afraid? A bad feeling settles in Sans' stomach, and he took a deep breath. "this human… they're dangerous?" He asked.

The sentry looked back at him, confused and scared and hopeless. Finally he opened his mouth, and Sans closed his eyes slowly as his words washed over him.

"My king… it's… it's the seventh human from last time," the monster whispered. "The human has returned to finish what they started."

Sans' phone started buzzing at that moment, and Sans didn't even have to look at the screen to know what it said.

 **ID CALLER: LUCKY#7**.


	5. Part Five

*This is the end.

* * *

Sans was leaning against the tree, gazing at the branches above. A few birds chirped at each other and took off, flying into the distance. Sans closed his eyes, taking deep breaths. Everyone was gone, evacuated from the area. If Sans fell, he would fall alone.

Feet crunched on leaves, and Sans opened his eyes.

The human stood a few feet away, staring determinedly into Sans' eyes. They had grown up some, sweater a different color and hair longer, but it was still the same kid. It was still Frisk.

"...Hi, Sans," the human said quietly. "...you didn't pick up my call."

Sans stared at the human, raising one eyebrow as he crossed his arms. He didn't say anything.

"I know what you're thinking!" Frisk added hurriedly. "But I… I don't have reset powers anymore, Sans... I lost my determination a long time ago. So I thought-"

" **buddy.** what did i say would happen if you ever entered my sight again?" Sans growled, cutting Frisk off.

Frisk flinched, looking as if Sans had slapped them. "I… I know," they whispered, not looking away as Sans' left eye flared blue and yellow. "That's why I came."

"to finish the job?"

"No." Frisk said firmly, lifting their chin. "...I wanted to do two things here, actually. One, to explain a bit- a bit better about why everything happened as they did and…" Frisk smiled, a tear slowly dripping down their face. "To pay for my deeds last time at least a little bit... by giving you my soul."

Sans froze, eyes widening. "what the… kid, what're you saying?"

"You don't have seven souls yet, right?" Frisk bit their lip, one arm holding the other as they seemed to shrink in on themself. "Because I released the other six. It won't fix everything… but…"

The two lapsed into silence, and Sans sighed. "fine. if you have some kind of excuse you want to tell me so bad that you're willing to die for it, go ahead."

Frisk stepped forwards, palms up to show they were empty. Sans watched them, his eye flaring as he tracked their movements carefully. "Did you know, Sans," they asked softly. "That once, the very first human to fall into the Underground was named Chara? They were the adopted child of King Asgore and Queen Toriel, and they killed themself to give their sibling their soul so they could get the other needed six human souls to open the barrier."

Sans hesitated, his smile slowly slipping away as he nodded. His journal had all the information, pieced together on a certain flower during a previous run. "Obviously, it failed. But Chara… Chara didn't die. Not completely. They were left alone, angry, hurt, confused…" Frisk studied their shoes. "Their soul was red, since determination was their main trait. So when I came along, they used that to slowly take over my body and my determination, using it to get back at everyone and everything. Not once, but many, many times." Frisk's shoulders started shaking, and Sans leaned his head back against the tree, studying the human.

"I fled the Underground just before they took everything from me, Sans. On the Surface, they couldn't make me reset anymore. And I waited. Waited until I felt guilty and lonely enough that my determination was almost completely gone, and Chara couldn't force me to do anything anymore. And then I came back."

Sans grimaced as everything clicked to make some kind of horrible, ironic sense. "oh." He pushed himself fully back onto his feet and he walked towards the human until Frisk and Sans were only a foot apart. "...and now you're just gonna give up just like that? no fight or anything?"

Frisk's lips parted into a wobbly smile. "Yeah. Maybe you can set things right, Sans… I've always been a screw up. I know you can do better with my soul than Chara or I ever did."

Sans stared at them, his pupils returning to their normal white dots as he sighed. "what about this chara you mentioned? they still here?"

Frisk hesitated, but nodded anyway, looking away. For a moment, Sans could have sworn their eyes glittered red.

There was no choice for Sans. Not really, with all of this twisted anger left inside of him, not to mention the fact that Frisk was trapped down here just like everyone else until Sans took one more soul. And there was this strange anomaly as well to factor into the equation. With the monsters of the Underground so afraid of Frisk… no. there really was no choice.

"...hey, kiddo?" He asked quietly.

"What?"

"come here?" Sans spread his arms, offering a sad grin. "i think you look like you need a hug."

Frisk blinked and then smiled, tears beginning to leave trails over their cheeks as understanding flashed through their eyes. They hesitantly approached, and Sans watched them, his face calm and giving nothing away.

Just as Frisk reached for Sans, he took a deep breath and raised his hand. Bones shot from the ground and stabbed the child through the chest, instantly draining their health.

Frisk staggered, falling forwards, and Sans caught them in his arms as their last HP points dwindled away to nothing. Their blood dripped down Sans' fingers, a bright, brilliant red, and Sans looked down into their face as they started shaking.

"...Heh," Frisk said weakly, blinking and smiling up at Sans even as tears continued to drip down their face. Their eyes flicked upwards to Sans' crown and they closed their eyes, their breaths coming quickly and weakly. "...You're wearing a crown after all... I thought you said... you weren't cut out to be the ruler, you liar..."

Sans shrugged, watching Frisk's soul pulse weakly as it left their body. "here's two things you should know about me, kiddo; i can't keep promises and i don't always tell the truth." He was silent for a moment, and then smiled sadly down at Frisk. "...although, frisk, for what it's worth…i'm sorry, too."

The seventh human's soul was red.

.

"If you give me the souls, I can reset for you."

"nope."

Flowey shifted, peering up at Sans in annoyance. "...You don't have any idea how to use the souls though."

Sans merely flashed Flowey the grinning mask he displayed for everyone, then returned his gaze to the barrier. "don't worry about me. i'm sure i can figure it out."

Sans took a deep breath, and the seven containers rose from the ground. Sans looked over them grimly before he stepped forward, hitting the button that released the souls.

He knew what he had to do now.

The seven souls rushed towards him, encircling him for a moment as Flowey watched from the shadows.

Sans grinned wryly. It seemed his problems always formed around him like this.

He closed his eyes, and absorbed the souls.

.

"I don't understand," Flowey told Sans months later. "You could have gone back! You could have destroyed humanity! ...Why did you decide to do this…?"

Sans shrugged, looking down at the new village for monsters on the surface. "...i realized that the kid was right about some things."

"What?"

"if i had reset with that much power, none of us would've remembered it. even my journal entries would've been wiped away." Sans sighed, tired. "it wouldn't have changed the ending. we'd be trapped in a loop, and none of us would've ever realized it. it all had to stop somewhere, so i might as well be the one to make that choice. frisk started the ending; i'm just finishing it."

Flowey scowled. "You don't know that's what has to happen for sure."  
"nah. but i'm not the kind of person who has to know the answers to everything."

The flower glanced out as the sun started to set, and Sans sat down beside him, resting his chin on his hand. "...Don't you miss him…?" Flowey finally asked. "Papyrus, I mean. Even if you were caught in a loop, you'd still get to see him again…"

Sans grinned, but by now his smiles had long since run out of joy. They was beginning to look more like permanent grimaces. "i could say the same about you, asriel."

Flowey flinched slightly, frowning, and the two lapsed back into silence. Flowey looked away. "Actually… I… I could have reset before you had taken the souls for yourself. After Frisk left, I regained control of the resets and _could have._ I just… If that really was Chara then… then they didn't care about me anymore. I didn't want to know for certain if…" The flower sighed. "You should have at least kept the human souls though," Flowey told him. "It would have been nice to have a body again..."

Sans shrugged. "eh. you're adjusting to the surface just fine, aren't ya? i don't want to risk anyone resetting anymore. besides, those kids… they deserve a good, long rest."

"Whatever."

The two stayed there, watching the stars come out, and finally Flowey turned to leave. "...I'm heading back," he said. "You coming?"

Sans turned to look at him, pupils bright white against their dark surroundings.

"nah," he said quietly. "i think i'm going to stay and watch the stars on my own for a while."

Flowey nodded, and turned away. "Hey...smiley trash bag," he said quietly. "I do get it. I still hate you but… you should know that you're actually making a really great ruler for the monsters. Not that you heard that from me."

"oh wow. heh, a compliment? flower ya feeling tonight, i think you might have a fever," Sans joked, winking at Flowey half-heartedly. He didn't like to tell puns that often anymore, but the desired effect was achieved when Flowey scoffed and vanished, heading back to the house Sans had offered to share with the only other creature that understood what he was going through.

Sans stayed up until the sun rose again, and then the monster king stood to head back down the mountain and take care of his kingdom.

He didn't say it, but he thought it all the same.

The eighth sacrificed soul was white.

* * *

 **A/N:** Annnnd that's it for this story! Thanks so, so much for reading my work, this is maybe one of my favorite pieces I've written to date. I basically just wrote the entire thing as a one-shot in the order I felt like doing, so it was much more easy to fix the plot and everything since this piece was finished before I posted the first chapter.

A great big shout out to my fabulous beta, FlightlessTree! I basically handed her 20 pages of angst and she was so nice as to take her time as to edit it and really improve my writing. If you want more stuff to read, check her work out!

I might do more neutral ending mini-series in the future. Don't know, they're a ton of fun. There should be more neutral fanfiction in my opinion, so much variety to write about^^

Thanks for reading!

 **Beta Notes:** don't mind me I'm just over here crying...

Sans you poor sad dude

Such a good story! The plot was entirely spot on, I really love the directions eternity chose to explore. It's so touching!


End file.
